10kV箱式变电站高压负荷开关的维护,应检查触头接触情况和灭弧装置的消耗程度,发现有异变应及时检修或调换。
参考答案:对
China's success in manned-spacecraft travel shows ________ our country has become one of the greatest powers in space research.
A.what
B.which
C./
D.it that
计重收费系统中的轴型轮胎识别器日常无需维护,但每()次检查一次可大大提高可靠性。